How to use blender 2.8 with a (thinkpad) pointing stick?
On Linux, by default, holding down the middle button and then tilting the TrackPoint generates scrollwheel events.  TrackPoint enthusiasts typically use this to scroll through Web pages/documents.  However, Blender will interpret this as a zoom command.  This behavior can be disabled, but not all desktop environments have a control for it (e.g. Xfce4 doesn't), and the command line incantation is a bit obtuse.
The following was tested on a Debian Sid system; you must have the package xinput installed.  If you have an older version of Linux, the incantation may need to be different, as the support framework has changed in the last two or three years.  First check to see which is your TrackPoint device using xinput list.  You will see output something like this:
⎡ Virtual core pointer                      id=2    [master pointer  (3)]
⎜   ↳ Virtual core XTEST pointer                id=4    [slave  pointer  (2)]
⎜   ↳ Synaptics TM3072-003                      id=12   [slave  pointer  (2)]
⎜   ↳ TPPS/2 IBM TrackPoint                     id=13   [slave  pointer  (2)]
⎣ Virtual core keyboard                     id=3    [master keyboard (2)]
    ↳ Virtual core XTEST keyboard               id=5    [slave  keyboard (3)]
    ↳ Power Button                              id=6    [slave  keyboard (3)]
    ↳ Video Bus                                 id=7    [slave  keyboard (3)]
    ↳ Sleep Button                              id=8    [slave  keyboard (3)]
    ↳ Integrated Camera: Integrated C           id=9    [slave  keyboard (3)]
    ↳ AT Translated Set 2 keyboard              id=10   [slave  keyboard (3)]
    ↳ ThinkPad Extra Buttons                    id=11   [slave  keyboard (3)]

It's the TrackPoint device whose properties we want to change.  We can specify it either by ID number or, as below, by name:
xinput --set-prop 'TPPS/2 IBM TrackPoint' &quot;libinput Scroll Method Enabled&quot; 0 0 0

This disables button-based scrolling on the TrackPoint.  Holding the middle button down while tilting the TrackPoint will now rotate the view.  Root privileges are not required.  This setting does not persist and must be reset on each login/reboot. To immediately re-enable TrackPoint scrolling use:
xinput --set-prop 'TPPS/2 IBM TrackPoint' &quot;libinput Scroll Method Enabled&quot; 0 0 1

For more information see this Web page, and also man 4 libinput to find out what the arguments mean.